A class that knows how to walk down the tree. None of the individual visit methods are implemented on this visitor, so it forces the consumer to implement each one that they need. For a default implementation that continues walking the tree, see the Visitor class.

Instance Methods

Calls accept on the given node if it is not nil, which in turn should call back into this visitor by calling the appropriate visit_* method.

Visits each node in nodes by calling accept on each one.

Visits the child nodes of node by calling accept on each one.